In order to comply with some regulations regarding information directed to partially sighted or blind people, it became necessary to print Braille messages on certain packaging and boxes, in particular on medicine packaging. The Braille printing process consists of pressing or embossing a surface of the box to reveal points in relief (or protrusions) allowing tactile reading of the messages.
It is already known to print Braille messages when converting a cardboard sheet in a flatbed diecutting press (or platen press) to form blanks ready to be processed by a folder-gluer so as to subsequently form packaging boxes.
A platen press works a in sequential manner (or discontinuously), i.e. the sheets passing through the press are stopped before each converting operation. In contrast, a folder-gluer works uninterruptedly, i.e. the blanks passing through the folder-gluer are processed during their continuous advance in the machine.
The productivity for obtaining packaging boxes from cardboard sheets will be called global productivity, it is the combination of the productivity of a platen press and a folder-gluer.
Usually, the Braille characters printing is achieved using an embossing tool in the shape of a plate mounted on a platen of the platen press. Like every tool of a platen press, assembly of the embossing tool requires long and fine adjustments, thereby reducing the productivity of the platen press and thus the global productivity. This drawback increases with the number of embossing tools mounted on a same platen.
Moreover, in background art, the embossed blanks which leave a platen press are to be fed into a folder-gluer. The folder-gluer is fed by a feeder having a function of feeding the folder-gluer blank by blank from a stack of blanks. In a stack of embossed blanks, the protrusions tend to nest into each other so that it is difficult to separate the blanks as they are fed. Nevertheless, if a blank manages to leave the stack, the protrusions of said blank are crushed by the stack, thus reducing the legibility of the Braille messages.
Another drawback related to the prior art is the difficulty in printing a Braille message close to an edge or close to a crease of the blank. Indeed, the cutting, creasing and embossing tools are held on the same platen by tool supports which require a certain space. Because of this space requirement, the approaching of the tools is limited.